True or False: The nuclear membrane is selectively permeable to ions and organic molecules.

The statement is false because the nuclear membrane, also known as the nuclear envelope, is not selectively permeable to ions and organic molecules in the way described. Instead, it contains nuclear pores that facilitate the movement of larger molecules and ions between the nucleus and the cytoplasm. While the nuclear envelope allows certain small ions and molecules to pass freely, larger macromolecules typically require specific transport mechanisms to move in and out of the nucleus. The selective permeability is primarily due to the nature of the nuclear pore complexes, which act as gatekeepers rather than sustaining a fully selective barrier like other cellular membranes. This composition and structure mean that the nuclear membrane allows some substances to pass while restricting others, but it is not accurately described as "selectively permeable" in the context provided, leading to the conclusion that the statement is false.